Bile duct cancer is often diagnosed after curative options are no longer available. Stent therapy is used to keep the ducts open and can be combined with photodynamic therapy (PDT) to extend life expectancy. PDT requires an injection of photosensitizer after which light of a particular wavelength is applied endoscopically to kill the cancer cells. Drawbacks include not only high costs and poor availability, but foremost that patients have to avoid direct sunlight for a period of weeks. Radio frequency ablation (RFA) together with stent implantation constitutes an alternative by which the cancer cells are killed through heat, also applied endoscopically. The RFA technology is more widely available and easier to deploy. However, it has not been studied extensively and no randomized trials exist comparing the two methods. This trial will compare survival in patients with a particular bile duct cancer depending on whether they receive PDT or RFA. Moreover, data will be collected on side-effects and quality of life.

Klatskin tumours are a form of bile duct cancer. They are generally not diagnosed until quite late and a curative operation is rarely a possibility. Their anatomic location usually results in bile duct obstruction and the aim of therapy is thus to keep the ducts open. This is accomplished through endoscopic retrograde cholangiopancreatography (ERCP) by implanting stents. Stent therapy combined with photodynamic therapy (PDT) extends life expectancy. PDT requires an injection of photosensitizer that is absorbed primarily by the cancer cells. Light of a particular wavelength is then applied with ERCP to kill the cancer cells. Drawbacks include not only high costs and poor availability, but foremost that patients have to avoid direct sunlight for a period of weeks. Radio frequency ablation (RFA) together with stent implantation constitutes an alternative by which the cancer cells are killed through heat applied during ERCP. The RFA technology is more widely available and easier to deploy. However, it has not been studied extensively and no randomized trials exist comparing the two methods. This trial will compare survival in patients with Klatskin tumours depending on whether they receive PDT or RFA. Moreover, data will be collected on side-effects and quality of life.

Inclusion Criteria:

1. Hilar cholangiocarcinoma (cytological or histological confirmation)
2. Surgery is not planned
3. Age ≥ 18 years
4. Written informed consent

Exclusion Criteria:

1. Tumour not accessible endoscopically
2. Known hypersensitivity to porphyrins or to any of the other ingredients of the photosensitizer chosen
3. Leukopenia (< 2000/mm3)
4. Thrombocytopenia (< 100,000 / mm³)
5. Severe, uncorrected coagulopathy (at the discretion of the physician)
6. Suspected erosion of major blood vessels, because of the risk of life-threatening mass haemorrhage exists
7. Porphyria (clinician's assessment) or other light-exacerbated diseases
8. Severely impaired liver and or kidney function (at the discretion of the physician)
9. Bedridden for more than 50% of the time (similar to ECOG (Eastern Cooperative Oncology Group) grade 3)
10. Planned surgical procedure within the next 30 days
11. Concurrent eye disease that will require a slit lamp examination within the next 30 days
12. Prior radiotherapy within the last four weeks
13. Previous PDT or RFA
14. Planned liver transplantation
15. Fertile women (within two years of their last menstruation) without appropriate contraceptive measures (implanon, injections, oral contraceptives, intrauterine devices, partner with vasectomy) while participating in the trial (participants using a hormone-based method have to be informed of possible effects of the trial medication on contraception)
16. Participation in other interventional trials
17. Patients under legal supervision or guardianship
18. Pregnant or nursing women